Oh I’m fully aware that python lets you cheat dependency injection with patch, its one of the many things python teaches developers to do wrong, which leads them to be unable to use any other language.
While my experience is mostly C++, I assume these mocking libraries are similar in allowing you to create a class that can report it’s own usage, and allow for arbitrary returns values and side effects, which is incredibly useful, especially in conjunction with dependency injection.
What patch lets you do is directly overwrite the functionality of private member functions on the fly, which if Java/JavaScript can do I’d love to know, I thought this was a uniquely Pythonic magic.
JS is also just as dynamic in this regard. Both JS and Python create and modify objects at runtime and use object fields instead of static definitions of methods or properties. It’s probably inherited from Smalltalk.
Quickest way to get a test suite so tightly coupled to structure rather than behavior that even just looking at the tests wrong makes them fail. But technically you do get test coverage I guess. Goodhart’s law in action.
my_get_mock = Mock(side_effect=Some exception("oh no"))
result = some_func(http_getter=my_get_mock)
There’s many ways of writing bad code and tests, but mocks and patches aren’t always a bad tool. But sure, you can definitely fuck things up with them.
Exactly, have fun trying to get test coverage without dependency injection
with patch("some_file.requests.get", side_effect=SomeException("oh no")): result = func_using_requests()Though not every language makes mocking as easy, and multiple responsibilities in a single function can quickly get messy.
Oh I’m fully aware that python lets you cheat dependency injection with patch, its one of the many things python teaches developers to do wrong, which leads them to be unable to use any other language.
I vaguely remember Java also has mocking libraries, as does JavaScript. (Though JavaScript isn’t a language I’d hold up as the ideal.)
While my experience is mostly C++, I assume these mocking libraries are similar in allowing you to create a class that can report it’s own usage, and allow for arbitrary returns values and side effects, which is incredibly useful, especially in conjunction with dependency injection.
What
patchlets you do is directly overwrite the functionality of private member functions on the fly, which if Java/JavaScript can do I’d love to know, I thought this was a uniquely Pythonic magic.JS is also just as dynamic in this regard. Both JS and Python create and modify objects at runtime and use object fields instead of static definitions of methods or properties. It’s probably inherited from Smalltalk.
Quickest way to get a test suite so tightly coupled to structure rather than behavior that even just looking at the tests wrong makes them fail. But technically you do get test coverage I guess. Goodhart’s law in action.
It’s not really that different from like
my_get_mock = Mock(side_effect=Some exception("oh no")) result = some_func(http_getter=my_get_mock)There’s many ways of writing bad code and tests, but mocks and patches aren’t always a bad tool. But sure, you can definitely fuck things up with them.